The monitoring of electric parameters, such as current, voltage, energy, power, etc., and particularly the measuring and calculating of electric parameters, provides valuable information for power utilities and their customers. Monitoring electric power is important to ensure that the electric power is effectively and efficiently generated, distributed and utilized. Knowledge about power parameters such as volts, amps, watts, phase relationship between waveforms, KWH, KVAR, KVARH, KVA, KVAH, power factor, frequency, etc., is a concern for utilities and industrial power users. In addition, monitoring electricity can be used for control and protection purposes.
Many metering functions in a power distribution system require concurrent knowledge of the states of multiple circuits or devices in the system to be communicated to a central command and control entity in order to work efficiently and effectively. However, a given power system rarely contains equipment from just one, or even just two, manufacturers. Within the power distribution or monitoring system, the various devices are often provided by multiple manufacturers and are configured to communicate with multiple different protocols.
Further, current metering devices in use are typically legacy or slave devices which are difficult to interface with and retrieve data from. These devices often require proprietary or custom software running on a central server or computer and thus data retrieval can often be complex or costly. In addition, such slave devices, as well as legacy devices, lack the advanced hardware or software, as well as the capability to be upgraded, to communicate in a modern client/server environment and interact using the open and non-proprietary protocols widely in use today.
Accordingly, is it is an object of the present invention to provide a system that overcomes the disadvantages of the prior art by integrating and consolidating the operations, communications and interactions of an electrical distribution system comprising a heterogeneous suite of inter-networked electrical metering devices as well as slave devices and loads, including legacy devices, for the purposes of protection, control and/or metering of electricity.
The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on those claims. By way of introduction, the preferred embodiments described below relate to an electrical distribution system architecture of electrical metering devices which are interconnected on a network. The metering devices further include capability to monitor and control attached slave devices, and provide capability to communicate between multiple devices in a variety of communication protocols.
The energy meter includes one or more sensors which are coupled with an electric circuit, the sensors operative to sense the electrical parameters in the circuit and generate analog signals which are representative of the electrical parameters. The analog signals are converted into digital samples using an analog to digital converter and a communications port facilitates communication of the digital signals to slave devices using a first protocol. The energy meter also includes a server module which allows for communication of the digital samples onto a digital network using a second protocol. In one embodiment the first and second protocols are the same and in an alternate embodiment the conversion between the first and second protocols is done on a processor internal to the energy meter.
According to a further aspect, there is provided a system for monitoring and controlling the distribution of electrical energy in an electric circuit. The system comprises a communications bus, a digital network and a master device. The master device comprises one or more sensors which are coupled with an electric circuit. The sensors are operative to sense the electrical parameters in the circuit and generate analog signals which are representative of the electrical parameters. The analog signals are converted into digital samples using an analog to digital converter and a communications port facilitates communication of the digital signals into a first protocol. The master device also includes a server module which allows for communication of the digital samples onto the digital network using a second protocol. The conversion between the first and second protocols is done on a processor internal to the master device. According to a further aspect, the system also includes the slave device.
Further aspects and advantages of the invention are discussed below in conjunction with preferred embodiments.